diff --git a/src/System.Private.CoreLib/shared/System/IO/Path.Unix.cs b/src/System.Private.CoreLib/shared/System/IO/Path.Unix.cs
index e5be5792085..1143c05208c 100644
--- a/src/System.Private.CoreLib/shared/System/IO/Path.Unix.cs
+++ b/src/System.Private.CoreLib/shared/System/IO/Path.Unix.cs
@@ -23,6 +23,9 @@ public static string GetFullPath(string path)
             if (path.Length == 0)
                 throw new ArgumentException(SR.Arg_PathEmpty, nameof(path));
 
+            if (path.IndexOf('\0') != -1)
+                throw new ArgumentException(SR.Argument_InvalidPathChars, nameof(path)); 
+            
             // Expand with current directory if necessary
             if (!IsPathRooted(path))
             {
diff --git a/src/System.Private.CoreLib/shared/System/IO/PathInternal.Unix.cs b/src/System.Private.CoreLib/shared/System/IO/PathInternal.Unix.cs
index 1113201e708..2f65a4252bc 100644
--- a/src/System.Private.CoreLib/shared/System/IO/PathInternal.Unix.cs
+++ b/src/System.Private.CoreLib/shared/System/IO/PathInternal.Unix.cs
@@ -22,13 +22,6 @@ internal static partial class PathInternal
 
         internal const string ParentDirectoryPrefix = @"../";
 
-        /// <summary>Returns a value indicating if the given path contains invalid characters.</summary>
-        internal static bool HasIllegalCharacters(string path)
-        {
-            Debug.Assert(path != null);
-            return path.IndexOf(InvalidPathChar) >= 0;
-        }
-
         internal static int GetRootLength(string path)
         {
             return path.Length > 0 && IsDirectorySeparator(path[0]) ? 1 : 0;
diff --git a/src/System.Private.CoreLib/shared/System/IO/PathInternal.Windows.cs b/src/System.Private.CoreLib/shared/System/IO/PathInternal.Windows.cs
index 2ab39286087..f315f43fd5b 100644
--- a/src/System.Private.CoreLib/shared/System/IO/PathInternal.Windows.cs
+++ b/src/System.Private.CoreLib/shared/System/IO/PathInternal.Windows.cs
@@ -146,36 +146,6 @@ internal static bool IsExtended(string path)
                 && path[3] == '\\';
         }
 
-        /// <summary>
-        /// Returns a value indicating if the given path contains invalid characters (", &lt;, &gt;, | 
-        /// NUL, or any ASCII char whose integer representation is in the range of 1 through 31).
-        /// Does not check for wild card characters ? and *.
-        /// </summary>
-        internal static bool HasIllegalCharacters(string path)
-        {
-            // This is equivalent to IndexOfAny(InvalidPathChars) >= 0,
-            // except faster since IndexOfAny grows slower as the input
-            // array grows larger.
-            // Since we know that some of the characters we're looking
-            // for are contiguous in the alphabet-- the path cannot contain
-            // characters 0-31-- we can optimize this for our specific use
-            // case and use simple comparison operations.
-
-            for (int i = 0; i < path.Length; i++)
-            {
-                char c = path[i];
-                if (c <= '|') // fast path for common case - '|' is highest illegal character
-                {
-                    if (c <= '\u001f' || c == '|')
-                    {
-                        return true;
-                    }
-                }
-            }
-
-            return false;
-        }
-
         /// <summary>
         /// Check for known wildcard characters. '*' and '?' are the most common ones.
         /// </summary>
diff --git a/src/System.Private.CoreLib/shared/System/Runtime/CompilerServices/IntrinsicAttribute.cs b/src/System.Private.CoreLib/shared/System/Runtime/CompilerServices/IntrinsicAttribute.cs
index dd01bacc491..381b4c63f7a 100644
--- a/src/System.Private.CoreLib/shared/System/Runtime/CompilerServices/IntrinsicAttribute.cs
+++ b/src/System.Private.CoreLib/shared/System/Runtime/CompilerServices/IntrinsicAttribute.cs
@@ -6,7 +6,8 @@ namespace System.Runtime.CompilerServices
 {
     // Calls to methods or references to fields marked with this attribute may be replaced at
     // some call sites with jit intrinsic expansions.
-    [AttributeUsage(AttributeTargets.Method | AttributeTargets.Constructor | AttributeTargets.Field, Inherited = false)]
+    // Types marked with this attribute may be specially treated by the rumtime/compiler.
+    [AttributeUsage(AttributeTargets.Struct | AttributeTargets.Method | AttributeTargets.Constructor | AttributeTargets.Field, Inherited = false)]
     internal sealed class IntrinsicAttribute : Attribute
     {
     }